On 18/2/16 14:02, Jiang Jiang wrote:
Hi Jonathan, I suppose not everyone have a chance to build and try this yet. By any chance you can provide a PDF test case demonstrating the feature? Then perhaps more people can comment.
Here's an example in Urdu script. There are 3 pages, all containing the exact same text.
Page 1 has \XeTeXinterwordspaceshaping = 0, so this is what existing xetex would produce.
Page 2 has \XeTeXinterwordspaceshaping = 1, which allows the font to kern across the inter-word spaces; in some cases this makes the space width substantially negative, so that adjacent words actually "overlap" to some degree. This avoids the large visual "gaps" that sometimes occur on page 1, depending on the shapes of the adjacent words.
Page 3 has \XeTeXinterwordspaceshaping = 2, so we get the exact same line-breaks as page 2, but with some (relatively subtle, mostly) improvements to the actual shaping at word boundaries.
Hope this helps to illustrate why this feature is important (in certain specialized cases).
JK
urdu.pdf
Description: Adobe PDF document
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